Polymer materials are utilized in an increasing number of categories of products, such as components for cars, boats, airplanes, within the electronics industry and other advanced industry as well as in paints and other coatings, for special packaging etc. The uses of polymer materials in new categories of products are only limited by the product properties. It is thus a continuous need for development of polymer products with improved properties e.g. with respect to increased scratch resistance, improved weather resistance, increased UV resistance, increased chemical resistance and improved properties with respect to antioxidation, anticorrosion etc.
In addition to pure polymer materials there has also been developed products based on materials that may be described as hybrids between inorganic and organic materials, which means that these materials are macro molecules that may have an inorganic core and organic branches.
Organic polymer molecules with branched structures have an enormous economical growth potential, particularly as components in new materials. So-called dendrimers are important examples of such polymer molecules with a perfectly branched structure as well as hyperbranched polymers with statistically progressive branching. Both dendrimers and hyperbranched polymers are denoted dendritic polymers. Dendritic (from Greec: “dendron”=tree) characterizes the principle of a progressive branching that is more or less perfect (G. R. Newkome, C. N. Moorefield, F. Vögtle, “Dendrimers and Dendrons: Concepts, Syntheses, Applications”, Wiley -VCH, Weinheim, (2001)). Formula 1 illustrates the principle difference between linear polymers and dendritic polymers (hyperbranched polymers and dendrimers).

Dendritic polymers are particularly interesting because the T units may carry functional groups and the density of available functional groups per weight or volume unit of the polymer is much higher than what is the case for linear polymers. Functional T groups may be used to impart a function in a material, like an antioxidant, a UV absorber, or a radical scavenger as described in WO publication No. 02092668. Alternatively the T groups may be used as very efficient cross-linkers of organic materials like epoxy resins or polyurethanes or as cross-linkers for thermoplastics. Due to the high degree of cross-linking between dendritic polymers and such organic compounds the dendritic polymers are superior cross-linkers compared to conventional cross-linkers like polyamines, polyalcohols, or multifunctional acrylates. Higher degree of cross-linking of an organic material like a cross-linked thermoplastic improves properties such as chemical resistance, weather resistance and wears resistance and makes the material useful for applications at higher temperature. (Hans Zweifel (ed.), Plastics Additives Handbook, Carl Hanser Verlag, München, (2001), 725-811). The T groups may also be used to organize the dendritic polymers in a network. As component in a material the dendritic polymer thus may induce improved barrier properties. Alternatively such dendritic polymers may be used as a binder or as a component in a thermoset plastic.
Dendrimers are usually manufactured in relatively complicated and expensive synthesis comprising several steps. The process conditions must be maintained very accurately in order to achieve a perfect progressive branch structure. Their industrial applications are therefore limited.
A general method of manufacture of hyper branched polymers was early described by Flory (P. J. Flory, Principles of Polymer Chemistry, Cornell University, (1953)). The polymerization of an AB2 monomer where A may react with B but where the reactions between A and A and between B and B are precluded, leads to a hyperbranched polymer.
Another way of manufacturing hyperbranched polymers involves the utilization of a reactive monomer that also carries an initiator, a so-called “inimer”. One example is the base catalyzed reaction between the inimer glycidol and the germ trimethylol propane as illustrated by Formula 2.

Hyperbranched polymers made in this way have properties that are quite similar to corresponding dendrimers (A. Sunder, R. Hanselmann, H. Frey, R. Muhlhaupt; Macromolecules, (1998), 32, 4240). This implies a much lower viscosity than that of linear polymers with a comparable number of free available HO-groups. A characteristic feature in the manufacturing process is that the inimer glycidol must be added very slowly to the germ and in a very thin dilution. Thus, the cost-efficiency of the process is severely reduced which is why the utility of hyperbranched polymers in industrial applications is quite limited.
It is previously known to perform certain modifications of the T groups of hyperbranched polymers. J.-P. Majoral, A.-M. Caminade and R. Kraemer, Anales de Quimica Int. Ed., (1997), 93, 415-421 describe the functionalization of dendrimers containing phosphorus. The functionalization of the T groups can be made with identical/similar chemical groups or with different chemical groups
FR 2761691 discusses dendrimers with functional groups at the surface that are modified through a reaction with cyclic thioesters. The reaction leads to a dendrimer surface with thiol groups that are attached to the dendrimer by amide or amine bondings. The products may be used as antioxidants. The dendrimers described are of the type polyamidoamine dendrimers (PAMAM dendrimers). PAMAM dendrimers contain tertiary amines that comparatively easy may be degraded after conversion to quaternary ammonium salts or aminoxides (A. W. Hofmann, Justus Liebigs Ann. Chem. (1851), 78, 253-286; A. C. Cope, E. R. Trumbull, Org. React. (1960), 11, 317-493; A. C. Cope, T. T. Foster, p. H. Towle, J. Am. Chem. Soc. (1949), 71, 3929-3935). Quaternary ammonium salts or aminoxides from amine based dendrimers can be formed when additives of amine based dendrimers are incorporated/compounded into thermoplastics with subsequent processing of the thermoplastics (e.g. film blowing, extrusion, casting). Such a degradation on one hand leads to a partial deterioration of the dendrimer core and on the other hand to formation of degradation products which may leak out and thereby reduce the surface quality of the polymer product. In addition tertiary amines may during processing of the thermoplastic form free radicals by decomposition of hydro peroxides (A. V. Tobolsky, R. B. Mesrobian, Organic Peroxides, (1954), Interscience Publishers, New York, p. 104-106). Dendrimers and hyperbranched polymers that contain tertiary amines thereby may induce an unintended degradation of thermoplastics during their processing, storage or use.
WO 01/48057 discusses multifunctional stabilizers against thermal oxidative degradation based on a core structure containing tertiary amines. As mentioned above this may lead to an unintended degradation of the core structure during processing, storage or use of (the) thermoplastics. The molar weight of a typical stabilizer manufactured in accordance with WO 01/48057 is 1246 g/mole
WO 97/19987 discusses combinations of polymer additives and modified dendrimers that may be used in polymer materials. In the exemplification of WO 97/199987 the dendrimers are based on polypropyleneimine (PPI) of 3rd, 4th and 5th generation thereby including 16, 32, and 64 terminal amine groups. The core structure contains tertiary amines which may lead to an unintended degradation of the core structure during processing, storage or use of thermoplastics. The modification of the PPI dendrimer with a fatty acid to form a multifunctional fatty acid amide may bee conducted by means of heating in a suitable solvent. The tertiary amine groups in the core structure of the dendrimer and primary amine groups at the dendrimer surface may in presence of oxygen contribute to partial degradation of the dendrimer structure. As explained above free radicals may be formed by decomposition of hydro peroxides. Such a partial degradation is indicated by a faint brown or yellow colour of the modified PPI dendrimer, like in examples I, XI, and XII in WO 97/19987. Typical molecule weights for modified PPI dendrimers in WO 97/19987 are in the range 10 000 to 40 000 g/mole. In WO 02/092668 surface activated hyperbranched or dendritic stabilizers comprising at least one additive group and a hyperbranched or dendritic core is discussed. In the exemplification of WO 02/092668 only dendritic cores based on 2,2-bis-(hydroxymethyl)-propionic acid is used. The dendritic core and the bonding to the additive group thereby are mainly based on ester bondings, which make the stabilizer sensitive to hydrolysis. In addition the exemplification of WO 02/092668 shows that the molecules of the prepared stabilizers as determined by gel permeation chromatography is between 1000 and 1500 grams/mole.
One type of particulate polymers with properties corresponding to the properties of hyperbranched polymers comprises an inorganic SixO(1.5)x-core with one T group per Si atom and is known as POSS (polyhedral oligosilesquioxanes). The most common compound of this class is a POSS with x=8 and substantially cubic structure (C. Sanchez, G. J. de A. A. Soler-Illia, F. Ribot, T. Lalot, C. R. Mayer, V. Cabuil; Chem. Mater., (2001), 13, 3066). The manufacture of POSS is expensive (M. C. Gravel, C. Zhang, M. Dinderman, R. M. Laine; Appl. Organometal. Chem., (1999), 13, 329-336 and WO 01/10871) and their industrial applicability is therefore limited.
Another type of particulate polymers with properties corresponding to the properties of hyperbranched polymers consists of an inorganic SixO(1.5)x core that carries one T group per Si atom and may be manufactured in a sol-gel process through controlled hydrolysis and condensation of a silane with a structureX—B—Si(—Y)3 where Y is chosen among hydrolysable residues and X—B basically corresponds to the T group. The process is described e.g. in Applicant's own WO publication No. 0208343. Sol-gel processes may be cost efficient so that they may be conducted in industrial scale from favourable raw materials and under mild conditions, i.e. without use of high pressures or high temperatures and without particular precautions like extreme dilution or the like. Thus particulate polymers with properties corresponding to properties of hyperbranched polymers manufactured by sol gel processes are industrially applicable in many areas.
Many examples of utilization of sol gel products in polymer products are known (DE 199 33 098, EP 666 290). Normally the main focus is placed upon the inorganic SixO(1.5)x core with a size in the nanometer range and thereby upon the sol-gel product as inorganic nano particle, cf. DE 199 33 098 and EP 486 469. The inorganic residues X—B are typically used to anchor the sol gel products in an organic matrix, cf. EP 486 469
The sol gel process involving hydrolysis and condensation of a silane in which the X—B group contains one or more amide groups is particularly simple because no external catalyst is needed and because the process may be conducted at ambient temperature or under moderate heating. One example is controlled hydrolysis and condensation of γ-aminopropyl trialkoxysilane as described in applicant's own patent application, WO publication No. 0208343. Controlled hydrolysis and condensation of silanes in which the X—B groups contains one or more amide groups typically leads to a sol in which the resulting particulate polymer product has an organic/inorganic structure (hybrid polymer) that is comparable with a hyperbranched polymer product with a number of more or less free amine groups in the T groups. Such organic/inorganic hybrid polymers exhibits a large number of functional T groups compared to their weight and/or volume. At the same time its compact structure compared to the structure of linear polymers ensures desirable properties like low viscosity and good admixing properties with thermoset plastics and thermoplastics. An example of an organic/inorganic hybrid polymer with properties corresponding to a hyperbranched polymer is shown by Formula 3.

Organic/inorganic hybrid polymers with properties corresponding to properties of hyperbranched polymers find utilization e.g. as additives for polymer products like thermoset plastics and in lacquers and other types of coatings for surface protection. Used in appropriate amounts and with convenient particle size such hybrid polymers may contribute to a significant improvement of the properties of the plastic material or the lacquer in question, hereunder an increased wear resistance/scratch resistance and/or weather resistance.
Prior art technology in the area sol gel processes/products may broadly be divided in four main categories as elaborated in more detail below, with reference to some examples or publications.
A first category concerns modification of non-hydrolysed amine containing silanes (DE 2023968, WO 03/029361, EP 0253770, EP 666290), commonly with bi-functional epoxy compounds (like e.g. JP 2001192485 ), and use of same in thermoplastics or in coatings. Hydrolysis and condensation are in some cases subsequently conducted but prior to its addition to the thermoplastics or coating in question. In general this method leads to an undefined distribution of molecular sizes with many large molecules. This implies that a subsequent hydrolysis is difficult to conduct with great success, since water will not reach all sites of the very large molecules. A low degree of hydrolysis implies a lower scratch resistance and a lower weather resistance for the product. A further disadvantage is that the water used for the hydrolysis in presence of the organic parts of the molecule may react in an undesired manner with active groups of said organic parts. Utilization of non-hydrolysed alkoxysilane compounds in a thermoplastic or thermoset plastic material implies that alcohols like ethanol and methanol are formed during the subsequent, slow hydrolysis of the silane compound, i.e. subsequent to the plastic material having been exposed to water. This may lead to reduced mechanical properties of the thermoplastic or the coating. In addition the formation of alcohols such as ethanol and/or methanol may cause migration of additives and/or degradation products to the surface of a thermoplastic or a coating, which may reduce the surface quality severely.
Another category of prior art methods concerns modification of nitrogen containing sol gel products by chemical reactions in which amine groups are not directly involved (S. kar, P. Joly, M. Granier, O. Melnyk, J.-O. Durand, Eur. J. Org Chem.; (2003), 4132-4139) or are not important (U.S. Pat. No. 5,744,243). The latter publication describes a coating composition that is achieved by mixing a) an acid catalysed hydrolysis and condensation of silane and monomer and b) a polymerized solution of organic polymer that contains functions which are compatible with the silane monomer. The coating is used for light reflection.